Top portion of a welding helmet



FIG. 1 is a perspective view, showing the new design for a top portion of a welding helmet;

FIG. 2 is a left side view, the right side view being a mirror image thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a rear view thereof.

The broken line showing forms no part of the claimed design, and the shading is provided to illustrate contour only and is not an indication of texture, gloss, etc. 

The ornamental design for a top portion of a welding helmet, as shown and described. 